Quench current level-time characteristics of AC insulated multi-strand superconducting cables

The quench current level of a multi-strand superconducting (SC) cable for AC use varies with the magnitude of AC overcurrent. We have defined this feature as the quench current-time characteristic, i.e. the I/sub q/-t characteristic. In this paper, we experimentally compared the I/sub q/-t characteristics of two kinds of SC cables, with and without a low resistive stabilizing matrix. The results proved that the different I/sub q/-t characteristics were caused by the difference of the current redistribution process where each SC strand quenches successively. Furthermore, it was pointed out by numerical simulation using an equivalent electrical circuit model that the difference in resistivity of SC strand could be the reason for the various I/sub q/-t characteristics.